Electric signaling device



April 24, 1934. J. LOEFFLER 1,956,393

ELECTRIC SIGNALING DEVICE Filed Aug. 17. 1951 llllli Lauz's Ilioqffer INVENTOR Patented Apr. 24, 1934 ELECTRIC SIGNALING DEVICE Louis J. Loeffler, Stapleton, N. Y.

Application August 17,

3 Claims.

c armature so that one end is free and in such close proximity to the electromagnet that when the electroinagnet is energized the current will cause a vibration of the armature to produce a distinct and intensified. humming sound.

Another object of the invention is to provide electric signaling device which can be readily assembled, cheaply made and having a minimum number of parts.

The invention resides more particularly in the novel combinations described and claimed in the following specification, reference being had to the accompanying drawing in which:

Fig. 1 represents a plan view of the device with the diaphragm partly broken away.

Fig. 2 is a sectional view of the device and the cover thereon, taken along the line 22 of Fig. 1.

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1.

Fig. 4 is a plan view, on reduced scale, of the blank from which the U-shaped member forming part of the magnetic field is formed.

Referring to the drawing in detail, numeral designates a U-shaped element having a flat base, the free ends of the legs of which are bent inwardly at 5 to form flanges 6. Struck out from the legs of element 4. are lugs or ears which lay in the plane of the base of the U-shaped member and which are adapted to receive screws or nails for fastening the entire device to a base. This U- shaped member is made from a flat blank, illustrated in Fig. 4. This blank is rectangular in shape. The lugs 20 and the holes therein are stamped out at points on either side of the center of said blank. The bending lines 5 are shown in dotted lines in Fig. 4. The lines at which the blank is bent to form the legs of the U extend from one side of the blank to the other, each of said lines coinciding with the base of one of said lugs. These lines are shown as dotted lines in Fig. 4.

An armature 7 made of thin resilient steel is fastened by set screws 8 to the longer flange 6. The armature forms the upper part or top of the casing. At one end and to the bottom of the casing is secured a plate 9 having bent up sides 1931, Serial No. 557,494

containing terminals 11 connected to an alterhating source of electric energy. A direct cur-- rent, if desired, may be used in conjunction with a centrally located vibrator. The plate 9 with arms 10 is secured to the bottom of the casing so by screws or bolts 12, as shown in Fig. 3. A polepiece of iron 13 is secured to the bottom of the casing a is energized by the current passing through he hobbin 14 which creates the vibra tion or" the armature. The bobbin has a strand of wire 15 connected to the terminals 11. A piece 4 of insulating material or head 16 is placed both below and above the electromagnet and a metal plate placed there-over, as shown in Fig. l, and a key 18 secures the bobbin to the core. A cover 19 of thin metal or other material having openings in the side to accommodate the terminals is placed over the entire structure, as shown in Fig. 2.

It will be noted that the armature, being secured at one end to the flange 6, permits of a H large amount of vibration so that the eifect is somewhat that of a tuning fork and the humming noise is greatly increased.

I claim:

1. An electric signaling device comprising a U- shaped frame constructed of a single piece of sheet metal and constituting part of a magnetic circuit, the ends of said sheet metal having been bent to extend in the same direction normal to the hight of the U to form the legs of the U- shaped frame, the free ends of said legs being bent inwardly toward each other to form flanges in a plane parallel to the bight, a core of an electromagnet secured to the bight and extending in the same direction with and parallel to the legs, a coil on said core, a resilient armature having one of its ends secured to the flange on one of said legs and having its surface extending over said electromagnet and terminating in juxtaposition to the flange on said other leg, and; a cover completely enclosing the device and secured thereto by frictional engagement of its sides with the legs of said frame.

2. An electric signaling device comprising a U- shaped frame constructed of a single piece of sheet metal, the base of which is flat and together with the legs of which constitutes part of the magnetic circuit and the free ends of which legs are bent inwardly to form flanges, an electromagnet disposed between the legs of said frame, a resilient armature having one of its ends secured to the flange on one of said legs and having its surface extending over said electromagnet and terminating in juxtaposition to the 113 flange on said other leg, lugs struck out of said legs and lying in the plane of the flat base of said U-shaped member and adapted to receive securing means for securing said device to a base, and a cover completely enclosing the device and secured thereto by frictional engagement of its sides with the legs of said frame and having cut out portions to accommodate said lugs.

3. An article of manufacture comprising a rectangular plate of magnetic material, a pair of slits cut through said plate, said slits being arranged on either side of the transverse axis of said plate, each of said slits defining the sides and one end of an ear, the other end of the ear being integral with the plate, said plate being adapted to be bent along two lines, each of which extends transversely of the plate and passes through that end of one of the ears which is integral with the plate, whereby the plate, upon being so bent, forms a U-shaped member having a flat base and having said ears in the same plane with said fiat base and said plate being adapted to be further bent along two lines, each of which extends transversely of said plate at a point between one of said slits and the corresponding end of the plate whereby an inwardly directed flange can be formed at the free end of each of the legs of said U-shaped member.

LOUIS J. LOEFFLER. 

